Within the liver, insulin stimulates hepatic glycogen synthesis. Insulin promotes hepatic synthesis of fatty acids, which are released into the circulation as lipoproteins. Skeletal muscle effects of insulin include increased protein synthesis and increased glycogen synthesis. Within adipose tissue, insulin stimulates the processing of circulating lipoproteins to provide free fatty acids, facilitating triglyceride synthesis and storage by adipocytes; also directly inhibits the hydrolysis of triglycerides. In addition, insulin stimulates the cellular uptake of amino acids and increases cellular permeability to several ions, including potassium, magnesium, and phosphate. By activating sodium-potassium ATPases, insulin promotes the intracellular movement of potassium.

Normally secreted by the pancreas, insulin products are manufactured for pharmacologic use through recombinant DNA technology using either E. coli or Saccharomyces cerevisiae. Insulin degludec differs from human insulin by the omission of the amino acid threonine in position B-30 of the B-chain, and the subsequent addition of a side chain composed of glutamic acid and a C16 fatty acid. Insulins are categorized based on the onset, peak, and duration of effect (eg, rapid-, short-, intermediate-, and long-acting insulin). Insulin degludec is a long-acting, human insulin analog.

Onset of Action

~1 hour

Time to Peak

9 hours

Half-Life Elimination

~25 hours (independent of dose)

Protein Binding

>99% (albumin)

Use: Labeled Indications

Diabetes mellitus: To improve glycemic control in patients 1 year of age and older with type 1 or type 2 diabetes mellitus

Contraindications

Hypersensitivity to insulin degludec or any component of the formulation; during episodes of hypoglycemia

Documentation of allergenic cross-reactivity for insulin is limited. However, because of similarities in chemical structure and/or pharmacologic actions, the possibility of cross-sensitivity cannot be ruled out with certainty.

Dosing: Adult

Diabetes mellitus, type 1: SubQ:

Insulin degludec-specific dosing:

Insulin-naive: Initial: One-third to one-half the total daily insulin dose given as insulin degludec administered once daily; remainder of total daily dose should be given as a short- or rapid-acting insulin and divided between each daily meal (general rule for initial total daily insulin dose, 0.2 to 0.4 units/kg)

Insulin-experienced: Initiate with same unit dose as the total daily long or intermediate-acting insulin unit dose from which the patient is being converted.

Dosage adjustment: Individualize and titrate dose every 3 to 4 days based on patient’s metabolic needs, blood glucose monitoring results, and glycemic control goal.

Type 1: Note: Multiple daily doses or continuous subcutaneous infusions guided by blood glucose monitoring are the standard of diabetes care. Combinations of different insulin formulations are commonly used. The daily doses presented below are expressed as the total units/kg/day of all insulin formulations combined.

Initial total insulin dose: 0.2 to 0.6 units/kg/day in divided doses. Conservative initial doses of 0.2 to 0.4 units/kg/day are often recommended to avoid the potential for hypoglycemia.

Usual maintenance range: 0.5 to 1 units/kg/day in divided doses. An estimate of anticipated needs may be based on body weight and/or activity factors as follows:

Nonobese: 0.4 to 0.6 units/kg/day

Obese: 0.8 to 1.2 units/kg/day

Division of daily insulin requirement (“conventional therapy”): Generally, 50% to 75% of the total daily dose (TDD) is given as an intermediate-acting (eg, NPH) or a long-acting form of insulin (in 1 to 2 daily injections). The remaining portion of the TDD is then divided and administered before or at mealtimes (depending on the formulation) as a rapid-acting (eg, lispro, aspart, glulisine) or short-acting (regular) form of insulin.

Dosage adjustment: Dosage must be titrated to achieve glucose control and avoid hypoglycemia. Since combinations of agents are frequently used, dosage adjustment must address the individual component of the insulin regimen that most directly influences the blood glucose value in question, based on the known onset and duration of the insulin component. Treatment and monitoring regimens must be individualized.

Diabetes mellitus, type 2: SubQ:

Insulin degludec-specific dosing:

Manufacturer’s labeling:

Insulin-naive: Initial: 10 units once daily

Insulin-experienced: Initiate with same unit dose as the total daily long or intermediate-acting insulin unit dose

Dosage adjustment: Individualize and titrate dose every 3 to 4 days based on patient’s metabolic needs, blood glucose monitoring results, and glycemic control goal.

For hypoglycemia: If no clear reason for hypoglycemia, decrease dose by 4 units or by 10% to 20% (ADA 2017f)

Surgical patients: On the morning of surgery or procedure, give 60% to 80% of the usual dose of long-acting analogs (eg, detemir, glargine, or degludec) (ADA 2017d)

General considerations for insulin use in type 2 diabetes (off-label):

Timing of initiation: Dual therapy (metformin + a second antihyperglycemic agent) and then triple therapy (metformin + two antihyperglycemic agents) is recommended in patients who fail to achieve glycemic goals after ~3 months with lifestyle intervention and metformin monotherapy or dual therapy, respectively (unless contraindications to metformin exist). Preference is not given for which agent(s) should be added to metformin (drug choice should be individualized based on patient characteristics). If HbA1c target not achieved after ~3 months of triple therapy, consider initiating basal insulin (usually with metformin +/- other noninsulin agent) or if patient already receiving an optimally titrated basal insulin (ie, a long-acting insulin such as glargine, degludec, or detemir) as part of their regimen, consider combination injectable therapy (ADA 2017f).

Combination injectable therapy: If HbA1c target has not been met with basal insulin (ie, long-acting insulin such as glargine, degludec or detemir) (usually combined with metformin +/- other noninsulin agent), despite titrating basal insulin to provide acceptable fasting blood glucose concentrations, combination injectable therapy should be considered. Options include: adding a rapid-acting insulin (eg, lispro, aspart, glulisine) prior to largest meal or adding a GLP-1 receptor agonist or changing from basal insulin to a twice daily premixed insulin. If HbA1c still not adequately controlled, consider advancing from one rapid-acting insulin prior to largest meal to ‘basal-bolus’ regimen (ie, rapid-acting insulin administered before ≥2 meals) or consider advancing from a twice daily premixed insulin to a three times daily premixed insulin (ADA 2017f).

Patients with elevated HbA1C at therapy initiation: If HbA1c is ≥9% at initiation of therapy, dual therapy (metformin + a second antihyperglycemic agent) should be considered. If HbA1c ≥10%, blood glucose is ≥300 mg/dL or if patient is symptomatic (eg, polyuria, polydipsia), insulin therapy (with or without additional agents) should be considered (ADA 2017f).

Dosing: Geriatric

Refer to adult dosing.

Dosing: Pediatric

Diabetes mellitus, type 1:

Insulin degludec-specific dosing: Children and Adolescents: SubQ: Note: Not recommended for patients requiring less than 5 units of insulin degludec.

Insulin-experienced patients: Initiate insulin degludec at 80% of the total daily long- or intermediate-acting insulin unit dose from which the patient is being converted.

Dosage adjustment: Individualize and titrate dose every 3 to 4 days based on patient’s metabolic needs, blood glucose monitoring results, and glycemic control goal.

Missed dose: Decision to administer or withhold dose until next scheduled dose is based on clinical judgment; increase frequency of blood glucose monitoring until next scheduled dose.

General insulin dosing (off-label):

Note: Multiple daily doses are utilized and guided by blood glucose monitoring. Combinations of insulin formulations are commonly used. The daily doses presented below are expressed as the total units/kg/day of all insulin formulations used. Insulin degludec must be used in combination with a short-acting insulin.

Usual maintenance range: SubQ: 0.5 to 1 unit/kg/day in divided doses; doses must be individualized; however, an estimate can be determined based on phase of diabetes and level of maturity (ISPAD [Couper 2014]; ISPAD [Danne 2014])

Partial remission phase (Honeymoon phase): <0.5 units/kg/day

Prepubertal children (not in partial remission): 0.7 to 1 units/kg/day

Pubescent Children and Adolescents: During puberty, requirements may substantially increase to >1.2 unit/kg/day and in some cases up to 2 units/kg/day

Division of daily insulin requirement ("conventional therapy"): Generally, 50% to 75% of the daily insulin dose is given as an intermediate- or long-acting form of insulin (in 1 to 2 daily injections). The remaining portion of the 24-hour insulin requirement is divided and administered as either regular insulin or a rapid-acting form of insulin at the same time before breakfast and dinner.

Division of daily insulin requirement ("intensive therapy"): Basal insulin delivery with 1 or 2 doses of intermediate- or long-acting insulin formulations superimposed with doses of rapid- or very rapid-acting insulin formulations 3 or more times daily

Dosage adjustment: Dosage must be titrated to achieve glucose control and avoid hypoglycemia. Adjust dose to maintain premeal and bedtime glucose in target range. Since combinations of agents are frequently used, dosage adjustment must address the individual component of the insulin regimen which most directly influences the blood glucose value in question, based on the known onset and duration of the insulin component.

Diabetes mellitus, type 2:Note: Not recommended for patients requiring less than 5 units of insulin degludec.

Insulin-naive patients: Approximately one-third to one-half of the total daily insulin requirement administered as insulin degludec once daily; remainder of total daily dose should be given as a short- or rapid-acting insulin and divided between each daily meal (general rule for initial total daily insulin dose: 0.2 to 0.4 units/kg/day).

Insulin-experienced patients: Children and Adolescents: SubQ: Initiate insulin degludec at 80% of the total daily long or intermediate-acting insulin unit dose from which the patient is being converted.

Dosage adjustment: Individualize and titrate dose every 3 to 4 days based on patient’s metabolic needs, blood glucose monitoring results, and glycemic control goal.

Missed dose: Decision to administer or withhold dose until next scheduled dose is based on clinical judgment; increase frequency of blood glucose monitoring until next scheduled dose.

Dosing: Renal Impairment

There are no dosage adjustments provided in the manufacturer’s labeling; insulin requirements may be reduced due to changes in insulin clearance or metabolism; monitor blood glucose closely.

Dosing: Hepatic Impairment

There are no dosage adjustments provided in the manufacturer’s labeling; insulin requirements may be reduced due to changes in insulin clearance or metabolism; monitor blood glucose closely.

Administration

Subcutaneous: For subcutaneous administration into the thigh, upper arm, or abdomen; do not administer IM or IV, or in an insulin infusion pump. Rotate injection sites within the same region to reduce the risk of lipodystrophy. In adults, insulin degludec should be administered once daily at any time of the day; in pediatric patients, administer once daily at the same time every day. Do not perform dose conversion when using the FlexTouch pen. The dose window for both U-100 and U-200 FlexTouch pens show the number of insulin units to be delivered and no conversion is needed. U-200 FlexTouch pens do not allow odd numbered dosing of insulin units; patients requiring odd numbered doses should use the U-100 FlexTouch pen. Do not dilute or mix insulin degludec with any other insulin formulation or solution; do not transfer from the FlexTouch pen into a syringe for administration.

Dietary Considerations

Individualized medical nutrition therapy (MNT) based on ADA recommendations is an integral part of therapy.

Storage

Store not in use (unopened) pens at 2°C to 8°C (36°F to 46°F) until expiration date, or at room temperature below 30°C (86°F) for up to 56 days (8 weeks). Do not freeze or use if solution has been frozen. Do not store pens directly adjacent to the refrigerator cooling element.

Store in use (opened) pens at 2°C to 8°C (36°F to 46°F) or at room temperature (below 30°C [86°F]) for up to 56 days (8 weeks); protect from direct heat and light.

Glucagon-Like Peptide-1 Agonists: May enhance the hypoglycemic effect of Insulins. Management: Consider insulin dose reductions when used in combination with glucagon-like peptide-1 agonists. Avoid the use of lixisenatide in patients receiving both basal insulin and a sulfonylurea. Exceptions: Liraglutide. Consider therapy modification

Liraglutide: May enhance the hypoglycemic effect of Insulins. Management: If liraglutide is used for the treatment of diabetes (Victoza), consider insulin dose reductions. The combination of liraglutide and insulin should be avoided if liraglutide is used exclusively for weight loss (Saxenda). Consider therapy modification

Metreleptin: May enhance the hypoglycemic effect of Insulins. Management: Insulin dosage adjustments (including potentially large decreases) may be required to minimize the risk for hypoglycemia with concurrent use of metreleptin. Monitor closely. Consider therapy modification

Pioglitazone: May enhance the adverse/toxic effect of Insulins. Specifically, the risk for hypoglycemia, fluid retention, and heart failure may be increased with this combination. Management: If insulin is combined with pioglitazone, dose reductions should be considered to reduce the risk of hypoglycemia. Monitor patients for fluid retention and signs/symptoms of heart failure. Consider therapy modification

Pramlintide: May enhance the hypoglycemic effect of Insulins. Management: Upon initiation of pramlintide, decrease mealtime insulin dose by 50% to reduce the risk of hypoglycemia. Monitor blood glucose frequently and individualize further insulin dose adjustments based on glycemic control. Consider therapy modification

Quinolones: May enhance the hypoglycemic effect of Blood Glucose Lowering Agents. Quinolones may diminish the therapeutic effect of Blood Glucose Lowering Agents. Specifically, if an agent is being used to treat diabetes, loss of blood sugar control may occur with quinolone use. Monitor therapy

Rosiglitazone: Insulins may enhance the adverse/toxic effect of Rosiglitazone. Specifically, the risk of fluid retention, heart failure, and hypoglycemia may be increased with this combination. Avoid combination

Warnings/Precautions

• Hypoglycemia: The most common adverse effect of insulin is hypoglycemia. The timing of hypoglycemia differs among various insulin formulations. Hypoglycemia may result from increased work or exercise without eating; use of long-acting insulin preparations (eg, insulin degludec, insulin detemir, insulin glargine) may delay recovery from hypoglycemia. Profound and prolonged episodes of hypoglycemia may result in convulsions, unconsciousness, temporary or permanent brain damage or even death. Insulin requirements may be altered during illness, emotional disturbances or other stressors. Instruct patients to use caution with ethanol; may increase risk of hypoglycemia.

• Hypokalemia: Insulin (especially IV insulin) causes a shift of potassium from the extracellular space to the intracellular space, possibly producing hypokalemia. If left untreated, hypokalemia may result in respiratory paralysis, ventricular arrhythmia and even death. Use with caution in patients at risk for hypokalemia (eg, loop diuretic use). Monitor serum potassium and supplement potassium when necessary.

Disease-related concerns:

• Diabetic ketoacidosis: Should not be used in patients with diabetic ketoacidosis (DKA); use of an IV rapid acting or short acting insulin is preferred.

• Hepatic impairment: Use with caution in patients with hepatic impairment. Dosage requirements may be reduced.

• Renal impairment: Use with caution in patients with renal impairment. Dosage requirements may be reduced.

• Hospitalized patients with diabetes: Exclusive use of a sliding scale insulin regimen (insulin regular) in the inpatient hospital setting is strongly discouraged. In the critical care setting, continuous IV insulin infusion (insulin regular) has been shown to best achieve glycemic targets. In noncritically ill patients with either poor oral intake or taking nothing by mouth, basal insulin or basal plus bolus is preferred. In noncritically ill patients with adequate nutritional intake, a combination of basal insulin, nutritional, and correction components is preferred. An effective insulin regimen will achieve the goal glucose range without the risk of severe hypoglycemia. A blood glucose value <70 mg/dL should prompt a treatment regimen review and change, if necessary, to prevent further hypoglycemia (ADA 2017d).

• Obesity: A decrease in glucose lowering effect of insulin degludec with increasing body mass index (BMI) has been observed.

Dosage form specific issues:

• Multiple dose injection pens: According to the Centers for Disease Control and Prevention (CDC), pen-shaped injection devices should never be used for more than one person (even when the needle is changed) because of the risk of infection. The injection device should be clearly labeled with individual patient information to ensure that the correct pen is used (CDC 2012).

Other warnings/precautions:

• Administration: Insulin degludec is a clear solution, but it is NOT intended for IV or IM administration or via an insulin pump.

Pregnancy Considerations

In women with diabetes, maternal hyperglycemia can be associated with congenital malformations as well as adverse effects in the fetus, neonate, and the mother (ACOG 2005; ADA 2018c; Metzger 2007). To prevent adverse outcomes, prior to conception and throughout pregnancy maternal blood glucose and HbA1c should be kept as close to target goals as possible but without causing significant hypoglycemia (ADA 2018c; Blumer 2013; Lambert 2013).

Insulin requirements tend to fall during the first trimester of pregnancy and increase in the later trimesters, peaking at 28 to 32 weeks' gestation. Following delivery, insulin requirements decrease rapidly (ACOG 2005).

Insulin therapy is the preferred treatment of type 1 and type 2 diabetes in pregnant women, as well as GDM when pharmacologic therapy is needed (ACOG 190 2018; ADA 2018c). Information specific to insulin degludec use in pregnant women is limited (Milluzzo 2017).

Patient Education

• Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)

• Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.

Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for health care professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience,and judgment in diagnosing, treating, and advising patients.